We seek to understand and document all radio transmissions, legal and otherwise, as part of the radio listening hobby. We do not encourage any radio operations contrary to regulations. Always consult with the appropriate authorities if you have questions concerning what is permissible in your locale.

Author Topic: Tried a 270-030 replacement  (Read 1331 times)

Offline moof

  • Full Member
  • ***
  • Posts: 223
    • View Profile
    • Email
Tried a 270-030 replacement
« on: May 29, 2020, 1931 UTC »
2 mH 5A choke from Mouser.  Did it work? Yes, but a bit overdriven even at lower volume.  RA told me never found a replacement that sounded as good as the original Shack part and I believe him.  $5 for this experiment bypassing a choke in a working clone into a dummy load of course.
If you want to see exactly what I tried, part # 80-SC-05-20J

Offline redhat

  • DX Legend
  • ******
  • Posts: 1585
  • USA
  • Music is my drug.
    • View Profile
    • Email
Re: Tried a 270-030 replacement
« Reply #1 on: May 30, 2020, 0434 UTC »
Are you trying to build one from scratch, or fixing a broken one?

If starting fresh, why not try one of the cheapo PWM amps off amazon.  MUCH better audio and lower distortion, less weight, and heat!  Only downside, 24V supply required for 15W out.

Somewhere under the stars...
Airspy HF+, MLA-30/Mini-whip/Chi-Town Loop
Please send QSL's and reception reports to xfmshortwave [at] proton [d0t] me

Offline Stretchyman

  • Hero Member
  • *****
  • Posts: 650
    • View Profile
Re: Tried a 270-030 replacement
« Reply #2 on: May 30, 2020, 1659 UTC »
RH is right and even if you wanted an MT just wind your own, so simple if not a bit of a chore. 1000s of transformer manufacturers stock standard bobbins and lams.

The PWM amps will also give you excellent Bass response which you'd never get from a MT unless it was Massive!

Folk still seem hung up on using the same old parts that generally aren't available anymore.


Time to move on!

'It's better to give than receive' so why RX when you can TX!

         15W, 60W and 100W models available.

                   Buy one from me, NOW!



HFUnderground T-Shirt
HFUnderground Garden Flag
by MitchellTimeDesigns